With a rise in awareness of environmental problems, solar batteries have been receiving attention as a clean energy source in recent years. In general, solar cell modules each constituting a solar battery have a structure in which a transparent front substrate, a surface-side sealer sheet, a solar cell, an undersurface-side sealer sheet, and an undersurface protecting sheet are laminated in order when viewed from the side of a light-receiving surface, and have the function of generating electricity from sunlight incident on the solar cell.
With solar cells that generate electricity within solar cell modules, generally, a plurality of solar cells are provided within a solar cell module, and configured to generate necessary voltage and current by being connected in series and in parallel. To wire the plurality of the solar cells within the solar cell module, a collector sheet for solar cells, for example, is used which is made by laminating metal foil to be patterned as wiring on a surface of a base material, i.e., a resin sheet (see Patent Document 1). Then the metal foil as the wiring provided on the collector sheet for solar cells and the output electrodes of the solar cells are electrically joined together by soldering.
To provide the wiring on the surface of the resin sheet as the base material for the collector sheet for solar cells, the same method as that used to make printed wiring boards, for example, can be used; that is, the metal foil is laminated on the whole surface of the base material to begin with, and then etched into a desired wiring pattern by photolithography.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2007-081237